200mA/250mA/300mA Current-Limit Switches

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The MAX4789–MAX4794 family of switches feature internal current limiting to prevent damage to host devices due to faulty load conditions. These analog switches have a low 0.2Ω on-resistance and operate from 2.3V to 5.5V input voltage range. They are available with guaranteed 200mA, 250mA, and 300mA current limits, making them ideal for SDIO and other load switching applications.

When the switch is on and a load is connected to the port, a guaranteed blanking time of 14ms ensures that the transient voltages settle down. If after this blanking time the load current is greater than the current limit, the MAX4789, MAX4791, and MAX4793 enter a latch-off state where the switch is turned off and active-low FLAG is issued to the microprocessor. The switch can be turned on again by cycling the power or the ON pin.

The MAX4790, MAX4792, and MAX4794 have an autoretry feature where the switch turns off after the blanking time and then continuously checks to see if the overload condition is present. The switch remains on after the overload condition disappears.

The MAX4789-MAX4794 are available in 6-pin 3mm x 3mm TDFN and tiny space-saving 4-pin SOT143 packages. The MAX4789/MAX4791/MAX4793 are also available in a tiny 5-pin SOT23 package. For lower current current-limiting switches, refer to the MAX4785-MAX4788 data sheet.
MAX4789, MAX4790, MAX4791, MAX4792, MAX4793, MAX4794: Typical Operating Circuit MAX4789, MAX4790, MAX4791, MAX4792, MAX4793, MAX4794: Typical Operating Circuit Enlarge+

Key Features

  • Guaranteed Current Limit: 200mA, 250mA, 300mA
  • Thermal-Shutdown Protection
  • Reverse Current Protection
  • 0.2Ω On-Resistance
  • 14ms Guaranteed Blanking Time
  • Active-Low FLAG Function (MAX4789/MAX4791/MAX4793)
  • 80µA Supply Current
  • 8µA Latch-Off Current (MAX4789/MAX4791/MAX4793)
  • 0.01µA Shutdown Current
  • 2.3V to 5.5V Supply Range
  • Undervoltage Lockout
  • Fast Current-Limit Response Time (5µs)
  • TDFN and SOT23/SOT143 Packages


  • Cell Phones
  • Global Positioning Systems (GPS)
  • Handheld Devices
  • PDAs and Palmtop Devices
  • SDIO

See parametric specs for Current Limit and USB Power Switches (80)

Part NumberPower SwitchesCurrent Limit
Current Limit
Fault IndicatorCurrent Limit Accuracy
Current Limit Set ByRON
Oper. Temp.
minmaxtypminmaxSee Notes
MAX4789 1200200Yes20Preset0.22.35.5-40 to +85
$1.51 @1k
MAX4790 200200No-40 to +85
$1.26 @1k
MAX4791 250250Yes
-40 to +85
-40 to +105
MAX4793 300300Yes-40 to +85
$1.67 @1k
MAX4794 300300No-40 to +85
$1.39 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
Request Reliability Report for: MAX4794 
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Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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